Centrifugal valve for cream separators



1955 w. H. HARSTICK 2,700,392

CENTRIFUGAL VALVE FOR CREAM SEPARATORS 2 Shets-Sheet 1 Filed July 31, 1951 Illllilll'lfllld vllllllilllillllwl 1955 w. H. HARSTICK 2,700,392

CENTRIFUGAL VALVE FOR CREAM SEPARATORS Filed July 31, 1951 2 Sheets-Sheet 2 nited States Patent CENTRIFUGAL VALVE FOR CREAM SEPARATORS William H. Harstick, Oak Park, 11]., assignor to International Harvester Company, a corporation of New Jersey Application July 31, 1951, Serial No. 239,586

1 Claim. (Cl. 13756) This invention relates to an improved centrifugal valve. More specifically the invention relates to a centrifugally operable valve element for controlling the washing liquid discharge orifice of a power washing cream separator.

In applicants Patent 2,473,948 patented June 21, 1949, a speed controlled centrifugal valve is disclosed. The centrifugal valve shown in this patent consists of a spiral or coil spring which is enclosed within a sheath of rubber. The valve is of annular shape and is positioned adjacent to a substantially continuous discharge opening of a cream separating bowl. During normal high speeds of operation the valve is centrifugally expansible to engage and seal the discharge opening, whereupon the separating bowl functions in a normal separating manner. When the separating operation has been completed and it is desired to flush the cream separating bowl with a washing liquid, a washing liquid is delivered to the interior parts of the bowl, and upon a lowering of the speed of the bowl the centrifugal valve contracts to its normal position whereby the discharge opening is uncovered and washing liquid is flushed outwardly through the discharge orifice.

Due to the extremely high speeds of operation of a cream separating bowl, it is necessary to provide a centrifugal valve which will remain in a quiescent position until a certain high speed of operation is reached, whereupon the valve expands to close the discharge opening. The centrifugal valve also must be constructed to perform its function over long periods of time. With the valve disclosed in the above mentioned application, it Was discovered that under certain conditions the rubber sheath would tear away from the spring and thus these portions would not be firmly supported and would have a tendency to wedge outwardly inbetween the edges of the bowl adjacent the peripheral discharge orifice. Thus it was found that many of the centrifugal valves would break down during use. In the aforementioned patented disclosure the core or hollow annular space formed by the inner peripheral edges of the coils of the spring was completely hollow since the rubber sheath merely surrounded the outer peripheral surfaces of the spring. This type of construction also is disadvantageous since on occasions pin holes or other minute fissures might occur in the rubber sheath. In view of the fact that the center of the spring was completely hollow, a certain amount of breathing in and out would take place through such cracks or fissures. Thus washing liquid and milk residue might be trapped within the rubber sheath which could subsequently lead to contamination. It is a prime object therefore of this invention to provide an improved centrifugal valve ring which will overcome the disadvantages above mentioned.

It is another object of the invention to provide a centrifugal valve ring comprising an annular coil spring having a rubber sheath securely bonded to the coil spring in a manner wherein the spring serves to retain the rubber sheath in position during high speeds of rotation of a separating bowl.

It is a further object to provide an improved centrifugal valve for use with a cream separating bowl, the valve including an annular coil spring having a rubber sealing element connected thereto, the sealing element consisting of a core of rubber bonded to the inner peripheral surfaces of the coil spring and including a sheath of rubber covering the coil spring and being securely bonded thereto.

A still further object is to provide a centrifugal valve ring having an annular coil spring embedded in a sheath of rubber, the sheath of rubber being securely bonded to the coil spring and having an integral core coextensive with an annular space formed by the inner peripheral edge of the coils of the spring, the rubber core being connected to the outer sheath of rubber by integrally formed projections of rubber which extend radially outwardly between the coils of the spring and are securedly bonded thereto. I

These and further objects will become readily apparent from a reading of the specification when taken in connection with the accompanying sheet of drawings.

In the drawings:

Fig. 1 is a side elevational view of a cream separator including a tinware construction and a separating bowl contained therein, the view being shown partially in secgionlto disclose relevant interior parts of the separating Fig. 2 is a cross sectional view taken along the line 22 of Fig. 1.

Fig. 3 is a side elevational view of a centrifugal valve ring.

Fig. 4 is a cross sectional view of a portion of a valve ring taken along the line 4-4 of Fig. 3.

Fig. 5 is a cross sectional view in perspective of Sh0;'t section of the centrifugal valve member shown in Referring now particularly to Figs. 1 and 2, a centrifugal separator 10 comprises a bowl 11 having upper and lower bowl portions 12 and 13 respectively. The bowl portions 12 and 13 are held in assembled relation by means of an annular connecting ring 14.

As best shown in Figs. 1 and 2, the separating bowl 11 is provided with a plurality of circumferentially spaced openings 16 at its maximum internal periphery. The connecting ring 14 likewise is provided with a plurality of circumferentially spaced openings 17 which are in alignment with the openings 16 to provide for the discharge of liquids from the interior of the separating bowl 11. A disk pack 18 of conventional design is provided within the separating bowl 11. A milk feed tube 19 extends downwardly into the separating bowl for delivering liquids to be separated to a distributing chamber 20. A washing liquid delivery spout 21 is also positioned above the separating bowl 11 for delivering washing liquid to the interior parts of the bowl. A cream outlet 22 is provided at the lower end of the bowl and a skim milk discharge outlet 23 is provided at its top. The function of the separating bowl during the separation of liquids is conventional and it is believed that the related parts for performing this function need not be further described.

The bowl 11 is enclosed within a tinware construction 24, which includes a milk receiving receptacle 25 and a cream receptacle 26 as indicated.

Referring now particularly to Figs. 1 through 5, a centrifugal valve embodying the primary features of the invention is generally designated by the reference character 27. The centrifugal valve 27 comprises an annular coil spring 28 consisting of a plurality of circumferentially spaced but interconnected coils 29. The inner peripheral edges 30 of the individual coils 29 provide a core or annular space as indicated at 31 in Figs. 4 and 5.

A sealing element is generally indicated at 32. The sealing element 32 is of rubber or a rubber-like material throughout and comprises an outer annular sheath 33. The sheath 33 completely encloses the coil spring 28 and is securely bonded to the outer peripheral edges 34 of the individual coils 29.

As best shown in Figs. 4 and 5, the outer sheath 33 is provided with a plurality of radially inwardly extending rubber connecting portions 35. The rubber connecting portions 35 are likewise bonded to the coils 29 and extend inwardly whereupon they are connected or integrally formed with an annular core 36, the annular core 36 being disposed within the annular space 31. The connecting portions 34 thus firmly connect the outer sheath 33 with the inner core 36 which is disposed within the inner portion of the spring. As indicated by the reference character 37 in Figs. 4 and 5, all of the portions of the outer sheath 33, core 36, and connecting portions 35 adjacent to any of the coils 28 are securely bonded to said coils. The spring of course during manufacture is stretched sufliciently so that the outer adjacent coil portions are separated to permit the connecting portions 35 to be formed. In the manufacture of centrifugal valves of this type, the spring is first coated with an adhesive which is compatible with both the coil spring and the rubber material. Thus when the rubber in a molten state contacts the coil spring, all portions of the rubber are securely bonded to the metal to provide a substantially impervious rnass throughout the centrifugal valve.

In the power washing operation, water or washing liquid is delivered to the bowl 11 and the bowl speed is sufliciently reduced so that the centrifugal valve ring 27 will contract to permit the discharge of washing liquid through the discharge orifices 16 and 17 respectively. The novel centrifugal valve herein described has both the inner core and the exterior sheath of rubber securely bonded to the coil spring. The core is connected to the outer sheath by the radially extending connecting portions 35, these portions serving to further support the outer sheath and to firmly connect the same to the coil spring 28. This construction minimizes greatly the possibility of the outer sheath tearing free and away from the coil spring 28. Furthermore, the integral sheath and core minimizes the chances of contamination since no interior space is provided in the ring which might collect undesirable bacteria. sheath is provided despite the very high speeds of rotation occasioned during the operation of the separating bowl. Thus a centrifugal valve of this type may be utilized for long periods of time in a satisfactory manner.

In view of the fact that the inner core of the spring is completely covered with a core of rubber and in view of the inwardly extending connecting portions which connect the core and the outer sheath of rubber, the sealing element consists essentially of a complete impervious mass extending throughout. Thus the danger of contamination is greatly reduced since any tiny fissures Suflicient support for the outer t i or openings in the rubber sheathing will not have the natural tendency to breathe and thus absorb quantities of the liquid which might be the case if the interior core of the spring did not have the core of rubber disposed therein.

The advantages of the improvement thus have been clearly set forth and described. It must be understood that changes and modifications may be made Without departing from the spirit of the invention as disclosed nor the scope thereof as defined in the appended claim.

What is claimed is:

In a centrifugal separating bowl having a plurality of circumferentially extending peripheral discharge openings, a centrifugally operable valve positioned adjacent said discharge openings comprising a continuous annular spring having a plurality of interconnected circumferentially disposed coils, said spring having an inner annular space formed by the inner peripheral edges of said coils, a sealing element of rubber-like material connected to said spring, said sealing element including an annular core portion disposed within the inner annular space of said spring and coextensive therewith, said core portion being securely bonded to the inner edges of said coils, an outer sheath enclosing said spring, said sheath being securely bonded to the outer peripheral edges of said coils, and portions on said sheath extending inwardly between the spaces formed by adjacent coils of said spring, said portions being bonded to the coils of said spring and being integrally connected to the core portion to provide a solid impervious mass coextensive with said spring, said valve being centrifugally expansible for sealing said discharge openings.

References Cited in the file of this patent UNITED STATES PATENTS 1,100,172 Calcutt June 23, 1914 2,473,948 Harstick June 21, 1949 2,482,570 Acton Sept. 20, 1949 2,555,542 Hintz June 5, 1951 

